This invention relates to an apparatus such as a color image copier for forming color images. More particularly, this invention relates to an apparatus such as a copier for forming images of different colors in various controlled manners by feeding a copy sheet and a developer sheet one on top of the other.
Toner is usually used as the developer by a copier and the like for forming an image on the image receiving medium such as a copy paper sheet. The toner is usually a mixture of a resin material which becomes soft and melt when heated to a relatively low temperature and a dye or a pigment as a coloring agent such that not only black but also blue and red images can be formed. If it is desired to form an image in a metallic color such as gold or silver, however, the toner must be mixed with a metal, and if a metal is mixed with a toner, the electrostatic image formed on the surface of the photosensitive drum begins to run such that the quality of the image is significantly affected adversely. For this reason, images in metallic colors such as gold and silver have been considered impossible to obtain. It is therefore an object of the present invention to provide a simple apparatus for forming images in specified colors such as gold and silver.
In another aspect, the present invention relates to a copier and the like for forming a horizontally inverted image such that the left-hand side and the right-hand side of the original to be copied are inverted on the formed image. In order to obtain such an inverted image by using a copier of the like, methods have been proposed previously whereby the optical system inside the copier is manipulated such that the light beams incident on the photosensitive body are inverted. Methods of this type, however, are not practical because a complicated optical system would be required and the increase in the cost of the apparatus may be considered unreasonably high since inverted images are not required very frequently. It is therefore another object of the present invention to provide a simple apparatus for obtaining an inverted image without restructuring the optical system or the like inside the copier. In still another aspect, the present invention relates to an apparatus for simultaneously producing a plurality of images from a single sheet of original. Conventional methods of simultaneously producing more than one copy were represented by the so-called impact process such as the dot impact method and daisy wheel method whereby a plurality of carbon sheets or the like are superposed and instantaneous pressures are applied to them simultaneously. Thus, it has been considered impossible to produce two or more copies simultaneously by a copier or other image forming means such as laser printers and liquid crystal printers which do not rely on the impact process. It is therefore a further object of the present invention to provide a copier and the like for simultaneously producing a plurality of images from a single original.
In a still further aspect, the present invention relates to a copier and the like for obtaining a copy in which the colored and uncolored sections of an original are reversed. According to a method previously considered for this purpose, the electrostatic latent image formed on the surface of the photosensitive drum was inverted, but a complicated mechanism is required for inverting a latent image and the apparatus becomes expensive to manufacture. It is therefore a still further object of the present invention to provide a simple apparatus for obtaining an image with colored and uncolored sections of an original inverted without restructuring the interior of a copier or the like.